Ruler



Dec. 11, 1934. A. KUEcHr-:NMEISTER 1,984,273

RULER Filed July 28, 1933 Patented Dec. 11,1934- y Y UNITED STATES PATENTl OFFICE RULER Arthur Kuechenmester, St; Louis, Mo.

Application July28, 1933, Serial No. 682,700 9 claims. v(o1. 332-107) This invention relates to rulers. The term embodiments of the invention illustrated in the ruler is used herein in a general sense to include accompanying drawing, whereiny straight-edges, scales, T-squares, and analogous Fig. 1 is a perspective view partly in transverse drawing, cutting or scrbing instruments used by section; n

5 draftsmen, architects, engineers and students. Figs. 2, 3, 4, 5, 6 and 'Zare transverse'sectional 5 Rulers now on the market and commonly used views through one side only of the ruler, showing are of two general classes; firstly, those made variations of construction; and y of wood, or of wood with celluloid (pyroxylin) Figs- 3, 9 and l0 are tl'anSVelSe Sectional VieWS edges, and secondly, those made of metal. Wood showing still other variations or modications 10 by nature being hygroscopic is readily affected vof construction. n 10 by atmospheric changes and caused to Warp, The rulers ShOWn in the ,drawing eaeh eemcurl, bend or bow, and splinter. Therefore rulers DriSeS a bOdy 0f Sheety metal having attached of the first class, wholly or partly of wood, true thereto one or two ruling edges of celluloid. The on leaving the shop, are likely soon to become `terni Celluloid iS uSed in a general Sense t0 nuntrue. Retruing beingan expensive procedure, clude equivalent and preferably transparent mal5 it is cheaper and more expedient to replace an terials, such as bakelite. The sheet'metal is'prefoff true ruler than to attempt to retrue it. erably light in Weight and nOn-COrrOSiVe, Such aS Rulers having blades of wood, or of wood with aluminium. stainless steel, Alleshenymetel, brass, celluloid edges, are unsatisfactory for the further German Silver, ete.

reason that when of long lengths it is necessary The ruler illustrated in Fig- 1 eQInDrSeS `a 20 to build up the wood of laminations, cross grained sheet metal body portieriy 20 and two Celluloid in relation to each other, in an effort to prevent ruling edges 21 and 22. The bOdy DOrtOn has or minimize warping. This results in wood of three lngt'udinally eXtendng upwardly Opensuch thickness as to necessitate beveling the edge ing parallel corrugatiOnS 23, which give added 25 or edges to renable the user to work close to Vthe rigidity to the ruler, provide grooves in which to 25 drawing surface, whether said` edges are of wood laypenelS, Pens 0r Other drawing instruments, in the all wood type, or ofcelluloid in the wood and alSO Serve as guides to thek lingers, as in with celluloid edge type. Onthe other hand, if drawing long Straight lines. Along both edges the wooden center portion is4 made sufficiently 0f the bOdy portion 20 the sheet metal thereof is thin to obvate the necessity of beveling the edge bent Over and under at 24 in Va horizontal direc- 30 or edges, then said center portion warps laterally, ti0n,`thenee dOWhWard at 25 in a verteal direeten, giving the miler ar lateral spring or spread which and thene Outward and Slightly upward at 26, results in distorting drawn lines from parallelthus OrIning `outwardly Opening channels or ism. Rulers of the second class, that is au metal 'grooves for receiving the celluloid ruling edges rulers, now in commercial use are not satisfacand also adding rigidity t0 the .ruler- Eaeh ruling 35 tory because they mar or stain the paper, rust odge 21 and 22 has, .a longitudinally extending and pit, and are much more expensive than Shadow concave ,groolfool depression 27 in its wooden rulers because of the higher cost of metal bottom fao? noar'the {moer odge tholooff Each and also because, after milling, the edges must 11mg edge 1s mserted m lts coirresponomg Chan* 40 be trued by grinding with an abrasive Such as nel of the body portion andpiessure 1s kthen ap- 40 ua carborundum wheel this being an expensive .phed to compressfand close the Sheet metal Walls v 1 of the channel into secure4 gripping engagement Femm Whlh must be performed Slow y to with the ruling edge, the part 26 of the channel avoid overheating the metal. For such reasons Wan being forced into the Shallow groove 27, all

few metal rulers are used as compared to rulersv as shown in, Fig 1. The ruling edges 21 andk 22 45 of Wood o1 of Wood and oeudlod- `are thus permanently secured or joined to the The main Object realized by the present inl/'enbody portion 20. The bend of the metal between tion is the provision of an inexpensive ruler which the vWalls 2,5 and y26 of eah. channel, forms a 'avoids the defects and objectionable characterissmooth, narrow, convex, metallic, bearing surtics of the aforesaid two classes of rulers now face 28 which engages the paper and Supports the 50 commonly used and which is of such durability ruling edges (ink fact y,the entire ruler) slightly that it can safely be guaranteed to remain true. elevated from the ldrawing surface.`

Still other objects and advantages realized, some 'I'hese surfaces 28, extending the entire length of which are specifically set forth hereafter,will of 'therulen constitute runners by which the be readily understood by reference to the several ruler rides on, and minimize frictional engage- 55 Cil ment with, the drawing surface. Furthermore, the slight elevation of the bottom surfaces of the celluloid drawing edges above the drawing surface by said runners 28, minimizes the chances of blotting or smearing said drawing surface, especially when the ruler is moved away from a freshly drawn inked line. There is the further important advantage that the slight elevation of the bottom surfaces of the celluloid members out of contact with the drawing surface avoids scratching or chang of said bottom surfaces and thus preserves the transparency of the ruling edges.

The construction illustrated in Fig. 2 is similar to that shown in Fig. 1, except that the wall v24 of the channel is longer, the wall 26 bows away from the bottom surface of the vruling edge 2l and constitutes a slightly wider runner 28 which by its engagement with the paper supports said ruling edge at a somewhat higher elevation from the paper, and only the extreme edge of the wall 26 engages in a narrow groove 27 in the bottom surface of the rulingedge. K

The construction of Fig. 3 is similar to that of Fig. l2, except that the wall 26 is not bowed away from and is parallel to the under surface of the ruling edge, thus forming a flat surfaced riuiner 28 for engaging the surface of the paper and elevating the ruling edge from the drawing surface less than in Fig. 2.

The construction of Fig. Litis similarto that of Fig. 3, except that the wall 26 inclines upwardly into interlocking engagement with an angular groove in the under surface of the ruling edge 21. Ijliere, as in Fig. 1, there is a narrow smooth convevx bearing surface or runner 28 for engagement with the paper and slightly elevating the ruling edge from the drawing surface.

In the construction of Fig. 5 there is-no groove in the bottom surface of the ruling edge 2-1 engaged bythe wall 26 and rivets 29 are provided as an additional means of securing the ruling edge 21 in the channel at the edge of sheet metal body por- 20. VIn this instance the flat bottom surface of the wall '26 constitutes the runner 28 for engagingthe drawing surface. l

Fig. 6 illustrates a construction similar to'that of Fig. A5, except ythat the walls 24, 25 and 26 are not'integral with the body portion 20, but are formed from-a separate strip of sheet metal. K `The "constructionof Fig. -7 is similar to` that of Fig. 3, except that the wall 26 is at a higher elevation than the bottom surfaceof theruling edge 21 ,and the latter surface bears directlyupon the drawing surface. In this instance no metal touchesthedrawing surface.` 4

The construction `illustrated in Fig. 8 is the same as that shown in Fig. 2,-except that additional rigidity is'furnished by a sheet metal arch member 30, underlying the body portion 20, and sprung or snapped into place with its upstanding edges 31,31 closely engaging and interlocking with the walls 25, 25 respectively ofthe channels for the two ruling edges 21 and 22.

Another variation of the construction is shown in Fig. 9, wherein the bodyportion isformed of Atwo-sheets of metal placed face to face vand brazed,' welde d or soldered together-exceptat their edges, where thewall 24 of each channel is formed by the upper sheet, and the walls 25 and 26 of each channel are formed from the lower sheet. Other- Wise the construction -is simi-lar to that shown in Fig. 2.

Stilljanother' variation of construction shown in Fig.=10is similar to that ofFig.-9, except that the walls 25, 26 of the channels in which the ruling edges 21 and 22 are secured, are formed from strips of sheet metal secured to the underside of the body portion 20 by rivets 33.

rIhe celluloid members 21 and 22 may, or may not, as preferred, each have a beveled surface adjacent its instrument guiding edge, as shown at the right in Figs. 1 and 8.

As thus appears, rulers embodying the present invention do not require the use of cement or adhesive to secure the celluloid ruling edges to the sheet metal body portion. So far as known, the

only successful adhesive for securing together celluloid and metal is liquid celluloid, which is celluloid dissolved in acetone or some other solvent. When such liquid celluloid is so employed, the solvent present attacks and softens the celluloid. To re-harden :the lcelluloid it must be aged or cured from thirty to ninety days. Furthermore, where this adhesive comes into contact with the celluloid, the finish and polish of the latter is destroyed, making re-polishing necessary. All of these` diiculties are eliminated by the construction of the present invention.

Furthermore, rulers lembodying the present `invention are not entirely Adependent for rigidity upon the natural stifness of the sheet metalmiddle portion, added rigidity beingimparted thereto by the open Vbox-beam `ei`fect-i.^esulting from the metal walls of the channels which receive 4the celluloid ruling edges, and, v if desired, by corrugating the sheet metal middle portion. .In this manner suicient rigidity may be obtained While using thin light-weight sheet metal.

The feature `of the relatively vnarrow metallic surfaces or runners which contact vthe drawing surface is also highly advantageous in minimizing friction and preserving the .transparency -of 'the celluloid ruling edges by slightly elevating .the same out of contact with the-drawing surface and thereby avoiding scratchingor chang of thebottom surfaces of said celluloid members. The elevation of said celluloid edges slightly-abovelthe work or drawing surface also prevents ink from collecting in the angle formedby the drawing edges and the drawing surface.

What is claimed is:

1. lIn a ruler, a'body portion havinga channel along one side thereof, both'saidbody portion and the Wall of said channel being of sheet metal, and a non-metallic 'ruling edge having apart thereof along one sidelocatedin saidchannel, the top, bottom and -end portions of vthe-wall of vsaid channel'being compressed into xed engagement with corresponding portions of the surface ofthe enclosed part of said ruling edge, thereby iforining a permanent and immovable joint-between said body portion and ruling edge.

2. 'In a ruler,'a bodyportionhavinga channel along one side thereof, both saidbody portion and the wall of said channel'being of sheet'metal, and `a nonmetallic 4ruling `edge lhaving a "part thereofl along one side locatedin'saibl channel and a longitudinally extending groove-in said part,the top,'bottom and end portions ofthe walll'of said channel being compressed intoxed engagement with corresponding portions of the surfaceofthe enclosed part of saidruling edge'and into said longitudinal groove ofthe enclosed part, thereby forming 'a permanent an'dirnmovable `joint between'said body portion vand ruling edge.

3. vA ruler comprising'fa -body portion having-'a channel along eachside thereof, saidbody portion and the wall of each channel being ofsheet metal; and two non-metallicy ruling` edges each' having a part thereof along one side located in one of said channels, the top, bottom and end portions of the wall of each channel being compressed into fixed engagement with corresponding portions of f the surface of the part of the ruling edge which it encloses, thereby forming a permanent and immovable joint between said body portion and ruling edges.

4. In a ruler, a body portion having a channel along one side thereof, both said body portion and the wall of said channel being of sheet metal; and a non-metallic ruling edge having a portion thereof along one side located in said channel, with a portion of the wall of the channel projecting below the bottom surface of the ruling edge and constituting a runner for engaging the drawing surface and elevating said ruling edge clear thereof.

5. In a ruler, a body portion having a channel along one side thereof, both said body portion and the wall of said channel being integrally formed from a single piece of sheet metal; and a nonmetallic ruling edge having a portion thereof along one side located in said channel, with a portion of the wall of the channel projecting below the bottom surface of the ruling edge and constituting a runner for engaging the drawing surface and elevating said ruling edge clear thereof.

6. In a ruler, a body portion having a channel along one side thereof, both said body portion and the wall of said channel being of sheet metal; and

a non-metallic ruling edge having a portion thereof along one side located in said channel, with a portion of Vthe wall of the channel projecting below the bottom surface of the ruling edge and having a curved surface constituting a runner for engaging the drawing surface and elevating said ruling edge clear thereof.

7. A ruler comprising an elongated sheet metal body portion having `a channel along veach side thereof and one or more longitudinal corrugations between said channels each corrugation forming an upwardly opening groove; and two nonmetallic drawing edges permanently secured in said channels respectively.

8. A ruler comprising a body portion having a channel along each side thereof, both said body portion and the wall of each channel being of sheet metal; and two non-metallic ruling edges each having a portion thereof located in one of said channels, the wall of each channel having a portion extending below the bottom surface of said ruling edge and constituting a runner for engaging the drawing surface.

9. A ruler comprising a body portion of sheet metal having a channel portion along each side redge thereof; non-metallic ruling edges secured in said channel portions respectively; and a reinforcing sheet metal arch member positioned beneath said body portion and between said channel portions. y

ARTHUR KUECHENMEISTER. 

